DIGITAL TELEVISION TRANSMITTING AND RECEIVING APPARATUS FOR TRANSMITTING AND RECEIVING DUAL STREAM USING 4-VSB STRONG DATA AND METHOD THEREFOR

摘要

PURPOSE: A digital television transmitting and receiving apparatus for transmitting and receiving a dual stream using 4-VSB(Vestigial Side Band) strong data and a method therefor are provided to improve the receiving performance of a receiving device by transmitting and receiving the dual stream formed as general data and strong data without increasing a mean power irrespective of a mixing rate of the dual stream. CONSTITUTION: A multiplexer(401) receives a digital image data stream. If strong data are included in the digital image data stream, a reinforcement encoder(411) encodes the strong data so that the strong data are mapped to one of two groups expressed as 4 levels. A trellis encoder encodes the strong data so that the strong data are mapped to groups expressed as 4 levels except for the two groups. A multiplexer(417) selectively inputs the strong data to one of the reinforcement encoder(411) and the trellis encoder. A pilot inserter/modulator/RF converter(419) performs the VSB modulation with respect to an output signal of one of the reinforcement encoder(411) and the trellis encoder, and transmits the modulated signal to a VSB receiving system.